One thing that bugs me, is you cannot promote groups directly... you have to create a Page for your group... even if the page is a useless placeholder.

Ha true. and you HAVE to download facebook's app on your phone (500MB app) to prove your not a russian troll. Do not even bother with the page, pages are facebook's way to trick you into paying endlessly to "boost your post"

Yeah, that's the other niggle, it's feels like a never ending stream of upsell/spam once you do make a page.